I recently replaced my head gasket and had the head checked/milled and a valve job done. I installed new APR head studs, new Toyota head gasket, new RV cam, steel guide timing chain, front cover, oil pump, water pump, hoses, injectors cleaned, full tune up and new radiator. The truck runs great lots more power and new injectors really smoothed out idle. The problem I am having is that when I bought the new radiator it is aluminum with plastic caps. My old 3-row brass radiator was fine but the hose necks crashed (my fault I over tightened with aviation style clamps and 20+ years old). Anyway, when I picked up the new radiator at Autozone I asked for a new radiator cap and they gave me the OE "small" style cap. I looked in the box and noticed that the new radiator they just sold me has a "big" style (larger diameter) cap. They said there computer shows only the small style but they looked up a 13lbs. large style cap and I bought it. Put the new radiator in filled it got the air pockets removed placed on cap and took it for a test drive. I went a few miles pulled back in the driveway and checked everything. The top of the radiator was wet but I figured I just spilt a little and did not give it much attention. So now a few weeks later and two different radiator caps later (one more 13lbs and 16lbs to see if it would hold better) and few cups of coolant after every trip I know for a fact my radiator cap leaks. I have drained my oil a few times to make sure my new head gasket is not leaking (oil looks like new no coolant). I even let the truck run with a funnel in the top of radiator to make sure I was not getting any exhaust in the coolant. So has any body else had this problem with the cheap aftermarket radiators not sealing at the cap? Do they take a special cap? Any help would be appreciated. I may pull the plugs and do a compression test just to make sure the head or head gasket are OK but I do not think that is the problem because the truck has not run so good in 330,000 + miles.

 

I would go back to Auto Zone and tell them I am glad that their radiators have a life time guarentee and take advantage of it.

 

yeah take the radiator back and get ur money back, and then go and get a 3 row brass one, oem or something that is stock, i have seen problems with those type where they split or pop at the bead easy and just not worth all the motor work u just did for that to happen, i went to the junk yard once and found a new 3 row that looked like it was a month old and got it for 50 bucks, but change it out....

 

I think I will just get a new brass radiator. I was just curious if anyone else has had a problem with the plastic/aluminum radiators. I just hate to have to drain the coolant one more time and mess with it again...